Line defaults incorrect after first parsing

When there are no lines on a canvas and you parse it for the first time upon restoring the transcription interface the default line showing is incorrect. This is because the default line presenter function does not fire when there are no lines when the canvas loads. This should be corrected.

Start at the default line presenter function and the canvas-load path used when restoring the transcription interface. Reproduce the first parse with no lines, then ensure the correct default line is shown and verify the behavior when lines are present as well.

Written by the indexing model from the issue text.